AVR-Chat

Back on the list!!

At 05:47 PM 15/06/2006, you wrote:
>make sure you pick the beam angles of the
>LED's you use for the display very carefully.

Don't know the angle yet. I'm looking at a pre built 7 segment
block. It has some 90 leds each segment but I will need to find
that out.

>20 degrees is a lot narrower than
>you think, and you could hardly see it unless you were dead in line.

I did some work on led traffic lanterns in the past and I understand
that, however some of the optical engineers that were specifying the
leds would go down to 7.5 deg!! so that they could get the brightness.
That was quite a while ago and leds have come a long way now.

>My sign has an RS485 link to the manager's PC inside the building where
>he can correct the time. It uses a Philips PCF8583 real time clock

That is one of the options I was thinking of. I'm using a Dallas DS1305
with the DS32KHz precision clock driver.

>It does daylight saving adjustments
>automatically (add 1 hour at 1am on last Sunday in March, back 1 hour at
>2am on last Sunday in October).

It would have to be programmable as some states don't have it at all and
others may start/stop at different dates i.e. Tasmania starts 1st Sunday
of October, QLD doesn't believe in it, NSW last Sunday of October etc :-(


Regards

John Samperi

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Ampertronics Pty. Ltd.
11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
Website  http://www.ampertronics.com.au
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